Hollow fiber membrane module

Abstract

A hollow fiber membrane module includes a pressure vessel, a plurality of hollow fiber membrane elements arranged in series inside the pressure vessel, and a connector that connects the hollow fiber membrane elements to each other. Each of the hollow fiber membrane elements includes a plurality of hollow fiber membranes, and a double-core tube extending in a longitudinal direction of the plurality of hollow fiber membrane elements. The connector includes a first channel and a second channel that do not communicate with each other. Between the hollow fiber membrane elements, the outer channels of the hollow fiber membrane elements are connected to each other through the first channel, the inner channels of the hollow fiber membrane elements are connected to each other through the second channel, and hollow portions of the hollow fiber membranes communicate with the inner channels through the second channel.

The invention claimed is: 
     
       1. A hollow fiber membrane module comprising:
 a pressure vessel; 
 a plurality of hollow fiber membrane elements arranged in series inside the pressure vessel; and 
 a connector that connects the hollow fiber membrane elements to each other, wherein 
 the pressure vessel includes:
 a feed port for a feed liquid provided on one end in a longitudinal direction; 
 a discharge port for the feed liquid provided on the other end in the longitudinal direction; and 
 a recovery port for permeated water, 
 
 each of the hollow fiber membrane elements includes:
 a plurality of hollow fiber membranes; and 
 a double-core tube extending in a longitudinal direction of the plurality of hollow fiber membrane elements, 
 
 the double-core tube includes a perforated distribution tube, and an inner tube disposed inside the perforated distribution tube, 
 an outer channel defined by an inner wall of the perforated distribution tube and an outer wall of the inner tube communicates with the feed port and the discharge port, 
 an inner channel defined by an inner wall of the inner tube communicates with the recovery port, 
 the connector includes a first channel and a second channel that do not communicate with each other, and 
 between the hollow fiber membrane elements, 
 the outer channels of the hollow fiber membrane elements are connected to each other through the first channel, and 
 the inner channels of the hollow fiber membrane elements are connected to each other through the second channel, and hollow portions of the hollow fiber membranes communicate with the inner channels through the second channel. 
 
     
     
       2. The hollow fiber membrane module according to  claim 1 , wherein a clearance extending in a longitudinal direction inside an inner wall of the pressure vessel is present between the hollow fiber membrane elements. 
     
     
       3. The hollow fiber membrane module according to  claim 1 , wherein the second channel includes a main channel for connecting the inner channels to each other, and a branch channel that allows the hollow portions of the hollow fiber membrane element to communicate with the main channel. 
     
     
       4. The hollow fiber membrane module according to  claim 1 , wherein the hollow fiber membrane element has a cylindrical shape, has an outer diameter of 10 to 28 cm, and has a total length of 1000 to 2000 mm. 
     
     
       5. The hollow fiber membrane module according to  claim 1 , wherein the plurality of hollow fiber membrane elements includes a hollow fiber membrane wound body including a plurality of hollow fiber membranes helically wound around the double-core tube. 
     
     
       6. A connector for connecting a plurality of hollow fiber membrane elements to each other, comprising
 a first channel and a second channel that do not communicate with each other, 
 an annular member fitted to outer peripheral faces of the connector, the annual member provided with a recess, 
 wherein between the hollow fiber membrane elements, outer channels of the hollow fiber membrane elements are connected to each other through the first channel, and inner channels of the hollow fiber membrane elements are connected to each other through the second channel, and 
 wherein the hollow fiber membranes communicate with the second channel through the recesses of the annular members. 
 
     
     
       7. The connector according to  claim 6 , wherein a hollow portion of a hollow fiber membrane communicates with the second channel of the connector. 
     
     
       8. The connector according to  claim 6 , wherein a material constituting the connector at least one selected from the group consisting of polyphenylene sulfide (PPS), polyphenylene ether (PPE), polyacetal (POM), polyvinyl chloride (PVC), polyetheretherketone (PEEK), and acrylonitrile-butadiene-styrene (ABS) resins. 
     
     
       9. The connector according to  claim 8 , wherein a linear expansion coefficient of the material is 11×10 −5 /° C. or less.